How the iTClamp Works

Thursday, November 7, 2013
Joseph Holley, MD

Essentially all mechanical hemorrhage-control techniques work by applying pressure, either directly or indirectly to the bleeding vessels (or proximal to the bleeding vessels in the case of tourniquets). The iTClamp also relies on pressure to control hemorrhage, but does so in a novel manner. It essentially converts an open bleeding wound into a closed wound, which then allows a stable clot to form in the contained space, ultimately tamponading the bleeding vessel.

The iTClamp is packed sterile and features two pressure bars connected by a hinge. Within this hinge is a one-way clutch, which allows the device to be closed and maintain pressure, but which prevents it from opening unless the release buttons are pressed. Along each pressure bar are four 21-gauge 4-mm-long needles, which serve to evert the skin edges during application and hold the device in place once closed.

During application, needles puncture the skin about 4.5 mm on average. As the iTClamp is closed, the edge of the skin is everted between the pressure bars. When fully closed, the pressure bars seal the wound along their surface horizontally and vertically, creating a completely air/fluid tight seal.

Once the iTClamp seals the wound closed, the blood will fill the wound pocket, forming a hematoma under pressure. As the pressure builds, the wound pocket will stretch slightly until the pressure in the wound equalizes with the pressure in the bleeding source. At this point, flow into the wound pocket will stop and hemorrhage will be controlled. Wounds that also have a tissue loss can be packed with gauze and/or a hemostatic agent before application of the iTClamp, ultimately lessening the amount of blood loss before a tamponading clot forms.

The CT angiography on p. 18 illustrates the formation of the hematoma within the wound pocket. In this case, since the vessel was only nicked (an arteriotomy) rather than transected, distal flow through the vessel was maintained. The clamp can effectively stop ongoing blood loss as long as the wound is amenable to a contained clot formation. Through-and-through wounds can be managed by application to both external wounds. The iTClamp is less likely to be effective in situations where the wound enters a large body cavity, as external containment will not stop internal hemorrhage.

The iTClamp can be applied within seconds, and can control hemorrhage within minutes. Utilized as a rapid, simple intervention, it should be considered as a life-sustaining intervention in situations such as those involving SALT triage. Although currently approved for extremity use only, an indication for the scalp should soon be approved, providing an effective means of quickly controlling significant bleeding, even in children.

A question that’s often raised during discussions of the iTClamp is how much pain results from application. Since the needles are small and penetrate simultaneously, and because they penetrate only superficially, pain has actually been reported as being very tolerable. Both volunteers with no injury and patients in the clinical setting typically report application pain around 2–3 on a 0–10 pain scale. Once in place, pain is minimal, typically described as an awareness that the device is present but not painful. A sensation of pressure at the site is the most common reported sensation from healthy volunteers.

The iTClamp has the advantage of being compact, simple and quickly applied; in many cases, it can replace a large, bulky dressing that can actually wick blood and its clotting components from the wound, thereby actually worsening bleeding. The device can also replace the need for a provider to maintain pressure on a bleeding site, freeing them to provide other life-saving care. Pressures formed within the now-sealed wound cavity will equalize with the bleeding vessel, automatically resulting in just enough pressure to control the hemorrhage.

The iTClamp can be removed and replaced in the field to ensure adequate wound sealing, but can also be left in place for several hours until definitive surgical care can be rendered. Animal studies have shown no short-term injury or damage to the wound where the clamp has been placed.
The iTClamp provides a novel way to quickly control life-threatening hemorrhage in a compact and easy-to-use device. Utilizing the body’s own natural processes, it is safe and effective. Training is intuitive and straightforward.